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From: "Bobby D. Bryant" <bdbryant@mail.utexas.edu>
Newsgroups: comp.lang.ada
Subject: Re: Is ther any sense in *= and matrices?
Date: Sun, 08 Jun 2003 16:56:39 -0600
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On Sun, 08 Jun 2003 11:51:31 -0700, Russ wrote:

> "John R. Strohm" <strohm@airmail.net> wrote in message
> news:<bbumef$fnq@library2.airnews.net>...

>> With all due respect, ladies and gentlemen, it has been known for a
>> very long time that the difference in "efficiency" between A := A + B
>> and A += B is lost in the noise floor compared to the improvements that
>> can be gotten by improving the algorithms involved.
> 
> Oh, really? I just did a test in C++ with 3x3 matrices. I added them
> together 10,000,000 times using "+", then "+=". The "+=" version took
> about 19 seconds, and the "+" version took about 55 seconds. That's just
> shy of a factor of 3, folks. If that's your "noise floor," I can't help
> wonder what kind of "algorithms" you are dealing with!

I'm just curious why the compiler didn't generate the same code for both
versions.

-- 
Bobby Bryant
Austin, Texas